(a) Field
The described technology generally relates to a light emission driver, a display device, and driving methods of the light emission driver and the display device.
(b) Description of the Related Technology
An organic light emitting diode (OLED) display uses an OLED of which luminance is controlled by a current or a voltage. An OLED generally includes a positive electrode layer and a negative electrode layer forming an electric field and an organic light emitting material emitting light by the electric field.
Generally, OLED displays are classified into a passive matrix OLED (PMOLED) and an active matrix OLED (AMOLED) according to how they are driven.
Among them, the AMOLED emitting light selected for each unit pixel from the viewpoint of resolution, a contrast, and operation speed has become the most commonly used.
The AMOLED generates light by flowing a current to a light emitting element, that is, the organic light emitting diode to thereby display an image. In this case, a driving transistor of each pixel flows a constant current according to a grayscale of image data.
In recent years, panels are becoming larger, and large-size panels have the problem of picture quality degradation caused by a voltage drop IR-drop across wires for supplying electrical power and data signals to pixels. A voltage lower than the actual applied voltage is supplied to the pixels due to the voltage drop across the wires, and this affects the amount of current flowing through the driving TFT, thereby causing luminance deterioration of the display device.